As it is known, a mobile radiocommunication network is adapted to provide voice, video and/or data services to a plurality of users, each user being provided with a respective mobile terminal. Examples of mobile radiocommunication networks are GSM networks (Global System for Mobile communications) or UMTS networks (Universal Mobile Telecommunications System).
In a mobile radiocommunication network, each user, with his own mobile terminal, is free to move within the geographical area covered by the network, thus changing both terrestrial coordinates and environment wherein he is situated. For instance, a user may typically move between indoor environments such as his home or his office, and outdoor environments of different types (urban environments, country environments, or the like). In the following description and in the claims, the term “environment” will designate the environment wherein a mobile terminal is situated, with particular regard to the existence and/or quality (e.g. configuration, consistency, etc) of physical structures surrounding the mobile terminal. Further, “indoor environment” will designate a substantially closed environment such as a building (apartment, house, office, . . . ). Conversely, “outdoor environment” will designate a substantially open environment such as a street, a garden, a country, a beach, . . . or an environment closed with light structures such as a vehicle compartment (car, train, etc.).
As it is known (Location Based Services), a service provider may offer to its users mobile radiocommunication services based on geographical location (e.g. defined by terrestrial coordinates) of mobile terminals of its users. For instance, a service provider may provide its users with a traffic report service, wherein each user only receives news relative to traffic in the geographic area wherein he is located. It is also known that the GPS network (Global Positioning System) may provide the geographical location of a GPS receiver, possibly integrated or associated to a mobile terminal.
Recently, service providers are more and more interested in offering to their users mobile radiocommunication services based on the environment wherein users are situated. For instance, a traffic report service similar to the above cited could be offered to users only after exiting their house. To this purpose, a service provider should be able to determine the environments wherein its users with their own mobile terminals are situated, possibly in addition to their geographical location.
US 2002/0050944 describes a method and apparatus for measurement processing of Satellite Positioning System (SPS) signals. A plurality of SPS signals from a corresponding plurality of SPS satellites are received in an SPS receiver. The signal environment corresponding to the location in which the SPS receiver is situated is characterized to produce signal environment data. In particular, the signal environment is classified as “indoor” or “outdoor”. In one embodiment described by US 2002/0050944, this information is derived from available GPS-based measurements. For example, the distribution of signal-to-noise ratio and/or signal attenuation and the satellite line-of-sight information (azimuth and elevation angles) may indicate an indoor environment as opposed to an outdoor environment. Signal attenuation is computed as the difference between the measured input signal level and the expected input signal level. According to US 2002/0050944, the signal environment may be identified as “indoor” if the signals for all satellites in-view are attenuated by a specified threshold level. In an alternative embodiment disclosed by US 2002/0050944, signal levels from a base station to a handset, are used to aid the signal environment determination.